(a) Field of the Invention
The present invention relates to a thermoplastic resin and preparation thereof, and particularly to an ABS thermoplastic resin and preparation thereof in which polymerization heat can be easily controlled even at a high rubber concentration and high total solid contents, and in which a monomer introduction method and introduction amount can be appropriately controlled to secure high impact strength and polymerization reproducibility.
(b) Description of the Related Art
Acrylonitrile-butadiene-styrene (hereinafter referred to as ABS) copolymer resin has superior qualities such as impact resistance, chemical resistance, processibility, and surface gloss, and thus it is used for monitor housings, game apparatus housings, electronic appliances, office equipment, etc., and the amount it is used tends to increase yearly. Changes in production line methods have increased yield by 1) reducing reaction time to reduce process time; 2) increasing total solid contents of latex; 3) increasing rubber contents in the latex; 4) decreasing rubber contents in final ABS injected or extruded articles, etc.
Among these methods, in order to 2) increase total solid contents and 3) increase rubber contents in the latex, monomers used in graft reaction are introduced in batches or they are continuously introduced. However, in the case of batch introduction with high total solid contents and high rubber contents, although these methods can obtain comparatively high impact resistance, because a cohered amount during polymerization is large and efficient graft reaction cannot be conducted, surface gloss and clearness drop due to a drop in dispersibility of rubber particles, and there is a difficulty in securing stable physical property values in mass-production. In addition, if such a batch introduction method is applied for mass-production, there are many difficulties in controlling an exothermic reaction heat amount, etc., and thus it has many problems in industrial applications.
Meanwhile, in the case of continuous introduction for preventing these problems, although it is favorable in terms of control of the exothermic reaction heat amount during polymerization, securing of latex stability, and surface gloss, etc., impact resistance and other physical properties of the final ABS product are inferior.